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  • wifi hardware switch doesn't work on a Dell 1018

    - by user42566
    I have a problem with my Dell 1018 Inspiron. I can't switch the wifi on, through the key on the keyboard. I think it's a driver problem since Ubuntu 11.10. This are the versions i tried: Ubuntu 10.04 / 10.10 It's possible to install the driver by hand: sudo add-apt-repository ppa:lexical/hwe-wireless sudo apt-get update sudo apt-get install rtl8192ce-dkms Ubuntu 11.04 It works out of the box Ubuntu 11.10 / 12.04 I haven’t found any solution for these versions. The "ppa:lexical/hwe-wireless" doesn't work for these versions. It says Can not find package rtl8192ce-dkms. The window of additional drivers is empty. So I can't install the driver. The wired network works good. Here is some information: 0: dell-wifi: Wireless LAN Soft blocked: no Hard blocked: no 1: phy0: Wireless LAN Soft blocked: no Hard blocked: yes sudo lshw -class network *-network description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:05:00.0 logical name: eth0 version: 05 serial: 5c:26:0a:0d:20:10 size: 10Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8105e-1.fw latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:43 ioport:2000(size=256) memory:f0f2c000-f0f2cfff memory:f0f18000-f0f1bfff *-network description: Wireless interface product: RTL8188CE 802.11b/g/n WiFi Adapter vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:07:00.0 logical name: wlan0 version: 01 serial: 70:f1:a1:fe:15:bd width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=rtl8192ce driverversion=3.2.0-22-generic-pae firmware=N/A ip=192.168.1.76 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 ioport:3000(size=256) memory:f0100000-f0103fff mark@mark-Inspiron-1018:~$ mark@mark-Inspiron-1018:~$ sudo lspci -nn 00:00.0 Host bridge [0600]: Intel Corporation N10 Family DMI Bridge [8086:a010] 00:02.0 VGA compatible controller [0300]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a011] 00:02.1 Display controller [0380]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a012] 00:1b.0 Audio device [0403]: Intel Corporation N10/ICH 7 Family High Definition Audio Controller [8086:27d8] (rev 02) 00:1c.0 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 1 [8086:27d0] (rev 02) 00:1c.1 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 2 [8086:27d2] (rev 02) 00:1d.0 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 [8086:27c8] (rev 02) 00:1d.1 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 [8086:27c9] (rev 02) 00:1d.2 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 [8086:27ca] (rev 02) 00:1d.3 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 [8086:27cb] (rev 02) 00:1d.7 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller [8086:27cc] (rev 02) 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev e2) 00:1f.0 ISA bridge [0601]: Intel Corporation NM10 Family LPC Controller [8086:27bc] (rev 02) 00:1f.2 SATA controller [0106]: Intel Corporation N10/ICH7 Family SATA Controller [AHCI mode] [8086:27c1] (rev 02) 00:1f.3 SMBus [0c05]: Intel Corporation N10/ICH 7 Family SMBus Controller [8086:27da] (rev 02) 05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 05) 07:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter [10ec:8176] (rev 01) mark@mark-Inspiron-1018:~$ mark@mark-Inspiron-1018:~$ lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID 174f:1127 Syntek mark@mark-Inspiron-1018:~$

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  • Abstraction, Politics, and Software Architecture

    Abstraction can be defined as a general concept and/or idea that lack any concrete details. Throughout history this type of thinking has led to an array of new ideas and innovations as well as increased confusion and conspiracy. If one was to look back at our history they will see that abstraction has been used in various forms throughout our past. When I was growing up I do not know how many times I heard politicians say “Leave no child left behind” or “No child left behind” as a major part of their campaign rhetoric in regards to a stance on education. As you can see their slogan is a perfect example of abstraction because it only offers a very general concept about improving our education system but they do not mention how they would like to do it. If they did then they would be adding concrete details to their abstraction thus turning it in to an actual working plan as to how we as a society can help children succeed in school and in life, but then they would not be using abstraction. By now I sure you are thinking what does abstraction have to do with software architecture. You are valid in thinking this way, but abstraction is a wonderful tool used in information technology especially in the world of software architecture. Abstraction is one method of extracting the concepts of an idea so that it can be understood and discussed by others of varying technical abilities and backgrounds. One ways in which I tend to extract my architectural design thoughts is through the use of basic diagrams to convey an idea for a system or a new feature for an existing application. This allows me to generically model an architectural design through the use of views and Unified Markup Language (UML). UML is a standard method for creating a 4+1 Architectural View Models. The 4+1 Architectural View Model consists of 4 views typically created with UML as well as a general description of the concept that is being expressed by a model. The 4+1 Architectural View Model: Logical View: Models a system’s end-user functionality. Development View: Models a system as a collection of components and connectors to illustrate how it is intended to be developed.  Process View: Models the interaction between system components and connectors as to indicate the activities of a system. Physical View: Models the placement of the collection of components and connectors of a system within a physical environment. Recently I had to use the concept of abstraction to express an idea for implementing a new security framework on an existing website. My concept would add session based management in order to properly secure and allow page access based on valid user credentials and last user activity.  I created a basic Process View by using UML diagrams to communicate the basic process flow of my changes in the application so that all of the projects stakeholders would be able to understand my idea. Additionally I created a Logical View on a whiteboard while conveying the process workflow with a few stakeholders to show how end-user will be affected by the new framework and gaining additional input about the design. After my Logical and Process Views were accepted I then started on creating a more detailed Development View in order to map how the system will be built based on the concept of components and connections based on the previously defined interactions. I really did not need to create a Physical view for this idea because we were updating an existing system that was already deployed based on an existing Physical View. What do you think about the use of abstraction in the development of software architecture? Please let me know.

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  • Azure Blob storage defrag

    - by kaleidoscope
    The Blob Storage is really handy for storing temporary data structures during a scaled-out distributed processing. Yet, the lifespan of those data structures should not exceed the one of the underlying operation, otherwise clutter and dead data could potentially start filling up your Blob Storage Temporary data in cloud computing is very similar to memory collection in object oriented languages, when it's not done automatically by the framework, temp data tends to leak. In particular, in cloud computing,  it's pretty easy to end up with storage leaks due to: Collection omission. App crash. Service interruption. All those events cause garbage to accumulate into your Blob Storage. Then, it must be noted that for most cloud apps, I/O costs are usually predominant compared to pure storage costs. Enumerating through your whole Blob Storage to clean the garbage is likely to be an expensive solution. Lokesh, M

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  • Willkommen in der Cloud. Aber nur mit den richtigen Standards.

    - by A&C Redaktion
    Cloud Computing ist das „In"-Thema, über das Anwender, Partner und Anbieter gleichermaßen heiß diskutieren. Reinhard Arnhold, Director Channel Sales, ist ein echter Kenner der Materie und zeigt im Video die unterschiedlichen Perspektiven auf, die ein ISV einnehmen kann. Die Geschäftsmodelle erfahren durch die Möglichkeit des Cludcomputings eine neue Dimension. Für welches Modell sich ISVs hierbei auch entscheiden, den richtigen Standard bei der Lösungsarchitektur zu wählen, das ist, so Reinhard Arnhold, eine der wichtigsten Erfolgsvoraussetzungen. Für ISVs, die aktuell noch keine Cloud Computing-fähigen Anwendungen haben, hat Reinhard Arnhold eine gute Botschaft. Oracle ist vorbereitet, mit der standardisierten Oracle Architektur den ISVs den Weg in die Cloud zu bahnen. Erlauben Sie ein kleines Wortspiel: Das ist der „Stairway to heaven". Es kann also ganz einfach sein, den geschäftlichen Himmel durch die Cloud zu erreichen.

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  • ArchBeat Link-o-Rama for 2012-08-28

    - by Bob Rhubart
    You may be tempted by IaaS, but you should PaaS on that or your database cloud journey will be a short one "The better option [to IaaS] is to rationalize the deployment stack so that VMs are needed only for exceptional cases," says B. R. Clouse. "By settling on a standard operating system and patch level, you create an infrastructure that potentially all of your databases can share. Now, the building block will be database instances or possibly schemas within databases. These components are the platforms on which you will deploy workloads, hence this is known as Platform as a Service (PaaS)." 'Shadow IT' can be the cloud's best friend | David Linthicum "I do not advocate that IT give up control and allow business units to adopt any old technology they want," says Infoworld cloud computing blogger David Linthicum. "However, IT needs to face reality: For the past three decades or so, corporate IT has been slow on the uptake around the use of productive new technologies." Do you agree? 9 ways cloud will impact IT employment | ZDNet ZDNet blogger Joe McKendrick condenses information from a recent report on how cloud computing will impact IT jobs. Number one on the list: New categories of jobs arising from cloud computing, which include "private cloud developers and administrators, departmental liaisons, integration specialists, cloud architects, and compliance specialists." Yeah, that's right, cloud architects. For more on cloud architects, including what you need to up your game to thrive in the cloud, check out "The Role of the Cloud Architect" on the OTN ArchBeat Podcast. Decisions, Decisions: The art, science, and politics of technology selection "When the time comes for a solution architect to make the final decision about the technologies, standards, and other elements that are to be incorporated into a particular project, what factors weigh most heavily on that decision? It comes as no surprise that among the architects I contacted, business needs top the list." Managing Oracle Exalogic Elastic Cloud with Oracle Enterprise Manager Ops Center Anand Akela's byline is on this post, but "Dr. Jürgen Fleischer, Oracle Enterprise Manager Ops Center Engineering" appears at the end of the post, so it's anybody's guess as to who wrote this thing. But the content includes a complete listing of the Exalogic 2.0.1 Tea Break Snippets series written by a member of the Exalogic team who goes by the name "The Old Toxophilist." So maybe the best thing to do here is ignore the names and focus on the very useful conent. Boost your infrastructure with Coherence into the Cloud | Nino Guarnacci Nino Guarnacci describes a use case that involved managing a variety of data caches that process complex queries and parallel computational operations, in order to maintain the caches in a consistent state on different server instances. Thought for the Day "No one hates software more than software developers." — Jeff Atwood Source: SoftwareQuotes

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  • Novos modelos de licenciamento para Web (Hosting, Cloud e SaaS) - Sessão para Parceiros - 15/Feb/11

    - by Claudia Costa
    RESERVE JÁ O SEU LUGAR!Com o aparecimento de novos modelos de 'deployment' de aplicações em Web - Hosting, On demand, Software-as-a-Service, Cloud Computing, etc - surgem também novas necessidades quanto às formas de licenciamento que permitam criar comerciais que suportem esses novos paradigmas. Neste encontro pretendemos actualizar os parceiros Oracle sobre os vários modelos de licenciamento disponíveis para estas novas forma de disponibilização das aplicações, dando-lhes a informação necessária e sugestões sobres as possíveis linhas de actuação que lhes permitam tirar partido destas novas oportunidades de negócio, e mostrar exemplos de como outros ISV já o estão a fazer. A quem se destina: Directores GeraisResponsáveis Comerciais Responsáveis de Marketing Equipas comerciais Responsáveis pela Gestão do Programa OPN e da relação com a Oracle Agenda What Oracle understands for ISV? Industry trends: Hosting, Cloud Computing e Software as a Service O que é que a Oracle entende por ISV? Revisão dos modelos de licenciamento tradicionais Full Use, Application Specific (ASFU) Novos modelos de licenciamento Hosting, Embedded (ESL), Embedded 'Royalty model', SaaS for ISV's, Proprietory Application Hosting, Modelos não standard Referências / Case Studies Discussão aberta Local e Horário9h30 - 12h30Oracle, Lagoas Park, Edifício 8, Porto SalvoInscrições: Enviar email para: [email protected] mais informações por favor contacte Claudia Costa pelo email ou telefone 21 423 50 27

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  • Multicore Expo

    Event to be held in conjunction with ESC Multi-core processor - Central processing unit - Parallel computing - X86 - Operating system

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  • Hardware wireless switch has no effect after suspend and 13.10 upgrade

    - by blaineh
    This seems to be a fairly chronic problem, as shown by the following questions: How do I fix a "Wireless is disabled by hardware switch" error? Wireless disabled by hardware switch "Wireless disabled by hardware switch" after suspend and other hardware buttons ineffective - how can I solve this? but no good solutions have been found! Wireless works fine after a reboot, but after a suspend the hardware switch (for my laptop this is f12) has no effect on the wireless, it is just permanently off, and shows that it is with a red LED. All My rfkill list all reads: 0: phy0: Wireless LAN Soft blocked: no Hard blocked: yes 1: hp-wifi: Wireless LAN Soft blocked: no Hard blocked: yes Any combination with rfkill <un>block wifi doesn't work, although one time first blocking then unblocking actually turned it on again. sudo lshw -C network reads: *-network DISABLED description: Wireless interface product: AR9285 Wireless Network Adapter (PCI-Express) vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:02:00.0 logical name: wlan0 version: 01 serial: 78:e4:00:65:2e:3f width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=ath9k driverversion=3.11.0-12-generic firmware=N/A ip=155.99.215.79 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 memory:90100000-9010ffff *-network DISABLED description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eth0 version: 02 serial: c8:0a:a9:89:b4:30 size: 10Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:42 ioport:2000(size=256) memory:90010000-90010fff memory:90000000-9000ffff memory:90020000-9002ffff Also, adding a /etc/pm/sleep.d/brcm.sh file as recommended here simply prevents the laptop from suspending at all, which of course is no good. This question has an answer urging to install the original driver, but it wasn't an "accepted answer" so I'd rather not take a chance on it. Also I'll admit I'm a bit lost on that and would like help doing so with the specific information I've given. xev shows that no internal event is triggered for my wireless switch (f12), but other function keys also acting as hardware switches work fine. I would be happy to provide more information, so long as you're willing to help me find it for you! This is a very annoying bug. I have a Compaq Presario CQ62. Edit. I just tried to reload bios defaults (or something) as shown by this video. Didn't work. Edit. I tried the contents of this answer, and it didn't work. Edit. I made a pastebin of dmesg. I couldn't even begin to understand the contents. Edit. Output of lspci | grep Network: 02:00.0 Network controller: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

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  • Errors when trying to compile the driver for the rtl8192su wireless adapter

    - by Tom Brito
    I have a wireless to usb adapter, and I'm having some trouble to install the drivers on Ubuntu. First of all, the readme says to use the make command, and I already got errors: $ make make[1]: Entering directory `/usr/src/linux-headers-2.6.35-22-generic' CC [M] /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c: In function ‘rtl8192_usb_probe’: /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12325: error: ‘struct net_device’ has no member named ‘open’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12326: error: ‘struct net_device’ has no member named ‘stop’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12327: error: ‘struct net_device’ has no member named ‘tx_timeout’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12328: error: ‘struct net_device’ has no member named ‘do_ioctl’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12329: error: ‘struct net_device’ has no member named ‘set_multicast_list’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12330: error: ‘struct net_device’ has no member named ‘set_mac_address’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12331: error: ‘struct net_device’ has no member named ‘get_stats’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12332: error: ‘struct net_device’ has no member named ‘hard_start_xmit’ make[2]: *** [/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o] Error 1 make[1]: *** [_module_/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u] Error 2 make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-22-generic' make: *** [all] Error 2 /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/ is the path where I copied the drivers on my computer. Any idea how to solve this? (I don't even know what the error is...) update: sudo lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: 03 serial: 78:e3:b5:e7:5f:6e size: 10MB/s capacity: 1GB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s resources: irq:42 ioport:d800(size=256) memory:fbeff000-fbefffff memory:faffc000-faffffff memory:fbec0000-fbedffff *-network DISABLED description: Wireless interface physical id: 2 logical name: wlan0 serial: 00:26:18:a1:ae:64 capabilities: ethernet physical wireless configuration: broadcast=yes multicast=yes wireless=802.11b/g sudo lspci 00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 18) 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18) 00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06) 00:1a.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06) 00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06) 00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06) 00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06) 00:1d.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06) 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a6) 00:1f.0 ISA bridge: Intel Corporation 5 Series Chipset LPC Interface Controller (rev 06) 00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller (rev 06) 00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06) 01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) 02:00.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6315 Series Firewire Controller (rev 01) sudo lsusb Bus 002 Device 003: ID 0bda:0158 Realtek Semiconductor Corp. USB 2.0 multicard reader Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 045e:00f9 Microsoft Corp. Wireless Desktop Receiver 3.1 Bus 001 Device 003: ID 0b05:1786 ASUSTek Computer, Inc. Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 6

    - by MarkPearl
    Learning Outcomes Discuss the physical characteristics of magnetic disks Describe how data is organized and accessed on a magnetic disk Discuss the parameters that play a role in the performance of magnetic disks Describe different optical memory devices Magnetic Disk The way data is stored on and retried from magnetic disks Data is recorded on and later retrieved form the disk via a conducting coil named the head (in many systems there are two heads) The writ mechanism exploits the fact that electricity flowing through a coil produces a magnetic field. Electric pulses are sent to the write head, and the resulting magnetic patterns are recorded on the surface below with different patterns for positive and negative currents The physical characteristics of a magnetic disk   Summarize from book   The factors that play a role in the performance of a disk Seek time – the time it takes to position the head at the track Rotational delay / latency – the time it takes for the beginning of the sector to reach the head Access time – the sum of the seek time and rotational delay Transfer time – the time it takes to transfer data RAID The rate of improvement in secondary storage performance has been considerably less than the rate for processors and main memory. Thus secondary storage has become a bit of a bottleneck. RAID works on the concept that if one disk can be pushed so far, additional gains in performance are to be had by using multiple parallel components. Points to note about RAID… RAID is a set of physical disk drives viewed by the operating system as a single logical drive Data is distributed across the physical drives of an array in a scheme known as striping Redundant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure (not supported by RAID 0 or RAID 1) Interesting to note that the increase in the number of drives, increases the probability of failure. To compensate for this decreased reliability RAID makes use of stored parity information that enables the recovery of data lost due to a disk failure.   The RAID scheme consists of 7 levels…   Category Level Description Disks Required Data Availability Large I/O Data Transfer Capacity Small I/O Request Rate Striping 0 Non Redundant N Lower than single disk Very high Very high for both read and write Mirroring 1 Mirrored 2N Higher than RAID 2 – 5 but lower than RAID 6 Higher than single disk Up to twice that of a signle disk for read Parallel Access 2 Redundant via Hamming Code N + m Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Parallel Access 3 Bit interleaved parity N + 1 Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Independent Access 4 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, significantly lower than single disk for write Similar to RAID 0 for read, significantly lower than single disk for write Independent Access 5 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, lower than single disk for write Similar to RAID 0 for read, generally  lower than single disk for write Independent Access 6 Block interleaved parity N + 2 Highest of all listed alternatives Similar to RAID 0 for read; lower than RAID 5 for write Similar to RAID 0 for read, significantly lower than RAID 5  for write   Read page 215 – 221 for detailed explanation on RAID levels Optical Memory There are a variety of optical-disk systems available. Read through the table on page 222 – 223 Some of the devices include… CD CD-ROM CD-R CD-RW DVD DVD-R DVD-RW Blue-Ray DVD Magnetic Tape Most modern systems use serial recording – data is lade out as a sequence of bits along each track. The typical recording used in serial is referred to as serpentine recording. In this technique when data is being recorded, the first set of bits is recorded along the whole length of the tape. When the end of the tape is reached the heads are repostioned to record a new track, and the tape is again recorded on its whole length, this time in the opposite direction. That process continued back and forth until the tape is full. To increase speed, the read-write head is capable of reading and writing a number of adjacent tracks simultaneously. Data is still recorded serially along individual tracks, but blocks in sequence are stored on adjacent tracks as suggested. A tape drive is a sequential access device. Magnetic tape was the first kind of secondary memory. It is still widely used as the lowest-cost, slowest speed member of the memory hierarchy.

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  • Sweden Azure Group with Michele Laroux Bustamente &amp; Maartin Balliauw Thursday 22nd May

    - by Alan Smith
    Originally posted on: http://geekswithblogs.net/asmith/archive/2014/05/19/156418.aspxSweden Azure Group (SWAG) has the privilege of welcoming Michele Laroux Bustamente and Maartin Balliauw to present sessions at our meeting this Thursday. Michele and Maartin are two of the world’s leading experts in Cloud Computing and Azure, and will be taking time out from their busy schedules to share their ideas with us, and answer any questions. Knowit Stockholm are kindly hosting the event at their offices, and providing food and refreshments. It should be a great evening. You can register for the event here. Azure Q & A - Michele Leroux Bustamante In this interactive Q & A session Michele Leroux Bustamante will be on hand to share her wealth of experience on Azure related issues. If you are new to Azure and wanting some tips to get started, or an experienced developer needing to negotiate the legal and political protocols related to Cloud Computing Michele will have been there, done that, and be willing to share her experiences. This session will be entirely driven by that attendees, so please come prepared with questions. Reducing latency on the web with the Windows Azure CDN – Maarten Balliauw Serving up content on the Internet is something our web sites do daily. But are we doing this in the fastest way possible? How are users in faraway countries experiencing our apps? Why do we have three webservers serving the same content over and over again? In this session, we’ll explore the Windows Azure Content Delivery Network or CDN, a service which makes it easy to serve up blobs, videos and other content from servers close to our users. We’ll explore simple file serving as well as some more advanced, dynamic edge caching scenarios. Michele Leroux Bustamante Michele Leroux Bustamante is CIO at Solliance (solliance.net), cofounder of Snapboard (snapboard.com), and is recognized as a Microsoft Regional Director and MVP. Michele is a thought leader with over 20 years specializing in building scalable and secure end-to-end system design, identity and access management, and cloud computing technologies – for companies of all sizes. In recent years Michele has also helped launch several startup business ventures and has been a mentor to startups in several accelerator programs – providing both technical and business guidance. Michele shares her experiences through presentations and keynotes all over the world, and has been publishing regularly in technology journals. Maarten Balliauw Maarten Balliauw is a Technical Evangelist at JetBrains. His interests are all web: ASP.NET MVC, PHP and Windows Azure. He’s a Microsoft Most Valuable Professional (MVP) for Azure and an ASPInsider. He has published many articles in both PHP and .NET literature such as MSDN magazine and PHP architect. Maarten is a frequent speaker at various national and international events such as MIX (Las Vegas), TechDays, DPC, …

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  • Oracle OpenWorld Call for MDM Papers

    - by david.butler(at)oracle.com
    As the MDM Track owner, I would like to invite everyone to respond to the Oracle OpenWorld (October 2-6, Moscone Center, San Francisco) Call for Papers (https://oracleus.wingateweb.com/portal/cfp/ ). The Call for Papers is open now through Sunday, March 27. This is an outstanding opportunity for organizations familiar with MDM to tell their story to a very large, knowledgeable and intensely interested community. Opportunities for feedback and networking abound.  I would love to see MDM papers on: business drivers; business benefits; quantified ROI stories; business process optimization; implementation styles; implementation lessons learned; using master data as a service; data governance best practices; end-to-end data quality experiences; support for SOA; Chart of Accounts issues fixed; how to leverage reference data; improving EPM and/or BI across the board; operationalizing a data warehouse; support for cloud computing; compliance success stories; architecture, scalability, and mixed workload RAC platform performance examples; industry specific value propositions (Financial Services; Retail, Telecom; Manufacturing, High Tech Manufacturing, Public Sector, Health Care, …); and line of business specific value propositions (CRM, ERP, PLM, SCM, …); etc. In fact, given that MDM positively impacts all areas of operations and analytics, there are no limits to the ideas you may have for an OpenWorld presentation. When you follow the submission process, be sure to use “Master Data Management” for either the Primary or Optional track. Add “Master Data Management” as an Optional track if you are adding MDM content to a presentation on one of the following tracks: Agile; Customer Relationship Management, Oracle E-Business Suite, Product Lifecycle Management, Siebel, Sourcing and Procurement, Supply Chain Management, or one of the 18 available industry tracks. If Cloud Computing is included, please add “Cloud Computing” as a Cross-Stream Track. And don’t forget to make “MDM” a Tag, along with Business Intelligence, Cloud, CRM, Data Integration, Data Migration, Data Warehousing, EPM, or Service-Oriented Architecture whenever your content includes these items. I will personally review each submission. I hope you all keep me very busy over the next few weeks.

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  • Ask the Readers: How Do You Customize Your Computer?

    - by Jason Fitzpatrick
    Whether you spend your energy customizing via case mods or leave the box stock and re-skin the OS, we’re interested in hearing all about how you customize your computing experience and make the machine yours. This week we want to hear about the OS tweaks, skins, modifications, and other tweaks you’ve applied to your computer to personalize it. Whether it’s minor tweaks at work because IT has the machines locked down or massive custom-built boxes at home that show off your love for your favorite Sci-Fi show, it’s time to share your favorite tools, tricks, and tips for customizing your computing experience–even better, share some screenshots or photos in the comments below. Don’t forget to check back in on Friday for the What You Said roundup! How to Stress Test the Hard Drives in Your PC or Server How To Customize Your Android Lock Screen with WidgetLocker The Best Free Portable Apps for Your Flash Drive Toolkit

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